Touchless Voltage Detector: What is It and How to Use

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A non-contact voltage tester, popularly known as a touchless voltage detector, is a device that helps detect power in a wire or outlet without touching it. The most modern detector effectively tests standard voltage in cables, circuit breakers, cords, lighting fixtures, and switches. It is powered by a battery and features LED to display results. 

Since electrical shocks aren’t pleasant, a non-contact voltage detector makes a useful tool to check for electricity. You can use the detector even for the lightest electrical work, such as installing a switch. It is a compact device that can be kept in a tool kit to use anytime.  

More About a Touchless Voltage Detector

While troubleshooting a thermostat or installing a new appliance, you need to cut off power to that outlet at the main electrical panel. Here, you can use a non-contact voltage tester to know if there is a wire that still has current. The device gives an indication when it comes close to a hot cable. The detector works well even when the wire is covered with some type of plastic insulator. 

How Does a Touchless Voltage Detector Work

A modern, non-contact detector features a range of components to detect voltage and display outcomes. They include:

  • Probe
  • Flashlight
  • LCD indicator
  • Power button
  • Sensitivity adjustment button
  • Battery compartment 

The detector’s bright LED showcases that it is working. Also, it works as a work light. It becomes red when it detects the voltage. Plus, a warning tone beeps with it. 

How to Use a Touchless Voltage Detector

Before starting to use the detector for your project, check whether or not it’s working by shoving its tip into a live electrical socket. If the non-contact voltage detector works fine, it displays a bright light and produces continuous chirps to indicate that the device has successfully detected voltage.  

In case you are working with a receptacle, insert its tip into the small plug slot. You can check all the slots if they are wired differently. On the other hand, if a receptacle is connected to a switch, ensure that the switch is on during the time of testing. Now, pull the receptacle out and test all the wires with the voltage detector to know if they are working or not. 

If you want to test a power switch with your touchless voltage detector, remove the switch’s cover plate and put the probe against the screw terminals. When the detector doesn’t indicate voltage, you can remove the switch and test other wires. 

You can also use the detector for light fixtures. Begin the process by turning off the circuit at the main panel. Before unscrewing the light bulb, ensure that its switch is on. Now, remove the bulb and place the tester’s probe onto the socket button. If it’s live, you can remove the electric box.


A touchless voltage tester is a safe, effective tool to check the voltage in a range of electric circuits without experiencing electrical shocks. Use it in the right way for all your projects!